Crusaders without key trio against Brumbies

The Crusaders will be without three experienced players - captain Richie McCaw, Brad Thorn and Leon MacDonald - for Saturday night's Super 14 rugby match against the ACT Brumbies in Canberra.

McCaw suffered a head knock in the round-one victory over the Chiefs last week and although he has improved significantly, according to concussion protocols he has not recovered sufficiently to play on Saturday.

Lock Thorn still has a heel injury and fullback MacDonald is still recovering from a shoulder injury sustained against the Chiefs.

George Whitelock will play in the number seven jersey, with Isaac Ross coming in for Thorn and Stephen Brett for MacDonald.

Flanker Kieran Read will captain the side.

Crusaders head coach Todd Blackadder says McCaw was close to being available but was not quite 100 per cent.

He says it's too early to say how long Thorn and MacDonald would be out for.